Ideally this would be an article in Brontë Studies, but I have no academic qualifications in their area, and I don't really enjoy the academic milieux. Nevertheless I may try to submit this at some point, but for now I just want to draw attention to the possibility. It is strange to me that no one seems to have suspected that Emily's well-known drawing of a fir tree, a gift to one of her Brussels friends, Louise de Bassompierre, contains a figure (and possibly a suggestion of eyes as well). This image has been popularised by Penguin and Norton editions of Emily's literary works. I don't remember when I first started seeing the figure, but it was years ago.
Below, I have cropped out these features in the drawing, and you can form your own opinion. The eyes are really just brows and the hint of the bridge of a nose, but the proportions are precisely right for a graceful feminine head in half-profile facing to the right and out of the drawing—or perhaps looking up at the (hidden, to us) front of the figure.
And as for that figure, it suggests a supernatural force, probably the North Wind, straining to the left and into the drawing, merging with the tree and blowing and bending the boughs. The figure as a whole suggests classical painting or sculpture; and the neck, head and hair, while vague, somehow agree with what we know of the personal appearances of Emily and Anne, based on Branwell's paintings and Charlotte's drawings. (We have more information about Anne than about Emily, and I am inclined to agree with the conclusions of brontesisters.co.uk regarding the surviving fragment from the ‘Gun Group’.)
Nothing more really needs to be said; the images speak for themselves, but some may still disagree that there is a figure intended, let alone the eyes. For me, the figure seems characteristic of Emily Brontë and adds a lot to the drawing. I have enhanced the North Wind figure in an artist's impression for use as the cover of the Brontë Ballads, but what you see below are details from the original drawing (by courtesy of the Brontë Society). Since I paid for the rights, I may as well also show the full original drawing.